The Internet is expanding rapidly in terms of the number of interconnected organizations or autonomous systems and the amount of data being routed among such organizations or systems. This growth affects the performance and reliability of data transfer, among Internet Service Providers, between enterprise service providers, within enterprise networks. One of the most difficult and important aspects of modern networking is properly deploying and maintaining routing policies for the routing of data among the ever-increasing number of autonomous systems and organizations. Sub-optimal Internet connectivity can lead to a poorly or inconsistently performing web site, adversely affecting a company's brand and reputation.
Border Gateway Protocol (BGP), the standard inter-domain routing protocol, has proven to be notoriously difficult to initially configure and even more complicated to correctly support. Furthermore, the concept of Autonomous Systems (ASs), which is integral to the protocol, hides routing metrics from the end systems resulting in sub-optimal routing decisions. The AS Path metric, which is an enumeration of the set of autonomous systems that a data packet travels through, is the primary metric BGP uses to select best path. This metric assumes that the shortest AS path metric is the best route to a given destination network; however, given the ever-increasing expansion of the Internet and the wide array of devices connected thereto, the AS Path metric is often not a very good predictor of the best path to a given destination network. Indeed, the default BGP metric does not account for other factors affecting routing path performance, such as link utilization, capacity, error rate or cost, when making routing decisions. In addition, BGP, version 4 (BSP4), the current BGP version, does not allow for adjustments necessitated by the consolidation that has taken and is currently taking place within the industry that has resulted in the collapse of smaller, formerly discrete networks into expansive, single autonomous networks. Consequently, the default BGP4 configuration often leads to poor network performance and creates reliability issues for many organizations.
Testing the performance characteristics of a particular route to a destination network is generally accomplished by transmitting test packets to a node in the destination network (and/or intermediate systems along the communications path) and monitoring for responses to the test packets. From the receipt, timing and type of response, as well as the number and size of the individual test packets, various route performance and other characteristics can be computed or inferred, such as 1) response time, 2) hop count, 3) available bandwidth, 4) jitter, 5) throughput, and 6) network loss. Probing a path to a destination network host with a series of test packets, however, is often problematic because a response is not generally guaranteed in many instances. For example, a firewall residing at the network destination gateway may intercept the test packets and, rather than returning a response, merely drops the test packets. In addition, such probe or test packets, when detected and reported by a firewall, may raise the ire of a network administrator who may view the test packets as suspicious hacker activity.
In light of the foregoing, a need in the art exists for methods, apparatuses and systems that address the issues presented by configuration and deployment of inter-domain routing policies. In addition, a need further exists for methods, apparatuses and systems that allow for augmentation of current routing policy metrics with more intelligent ones, leading to better routing decisions. In light of the foregoing, a further need in the art exists for methods and systems that maximize the likelihood of receiving responses to probe packets, while minimizing the perception that such probes are malicious or otherwise intrusive, to thereby facilitate testing the performance or other characteristics of a network path. Embodiments of the present invention substantially fulfill this need.